Green amaranth (Amaranthus powellii) belongs to a family of broad-leaved plants that produce grain seeds. The grains are high in protein. They are often ground into a flour, flaked or popped for consumption. Green amaranth is also grown as an ornamental garden plant for its green flower plumes and considered to be a weed in many parts of the nation such as Washington and Missouri, where it grows freely. In commercial operations the grain is harvested using a combine but a small farmer can easily harvest green amaranth grains by hand. Seeds are exceptionally small.
Shake the flower heads of the green amaranth after they have been on the plant for three months. If seeds begin to fall from the flower head then harvest can begin. Commercial harvesting operations that plan on using a combine system harvest after the first hard, killing frost, but the amaranth is ready for harvest weeks prior to this and can easily be done by hand in a small farm or garden. Another way to determine if the seeds are ready for harvest is to watch the birds. Numerous birds enjoy dining on green amaranth seeds. When the birds begin to eat the seeds it is time to harvest.
Grasp the flower head wearing a pair of gloves. Gently bend the flower head filled with seeds over into a five-gallon bucket. Shake the flower head briskly so the seeds are dispersed into the bucket. Harvest should take place during a dry day so the seeds are easily released from the plumes and do not stick.
Rub the flower head briskly with your gloved hand while holding it bent into the bucket to remove any final, stuck seeds. Seeds and parts of the flower head will fall into the bucket but can be sifted later. Once there are no more seeds on the flower head release it and repeat at the next flower head.
Empty the bucket of harvested green amaranth seeds onto a flat surface such as a table and work with your gloved hands gently to break away any chaff. Gently blow the chaff away using an air compressor so all that remains are the grains.
Set the green seeds/grains out in the sun to dry. Stir the seeds over the course of a few days until completely dried out and then store in an airtight container or zip-lock bag to prevent mold from developing. If unable to place in the sun due to weather the seeds can be placed inside next to a heat source to speed up the process of drying.